The present invention relates to the field of downhole drilling for oil, gas, and geothermal exploration. With a continually increasing demand for downhole drilling, the ability to drill more effectively through the use of electronics in a drill string has become more popular. Such electronics may be used to determine the direction of drilling, monitor the condition of the drilling equipment, and determine subsurface formation parameters.
U.S. patent publication 20050230149 which is herein incorporated by reference for all that it contains, discloses a method and apparatus for multiplexing data on-bit in a drilling operation. The apparatus comprises a bit; a plurality of transducers situated on the bit; and an analog multiplexer situated on the bit and capable of receiving the output of the transducers, multiplexing the received outputs, and transmitting the multiplexed outputs. The method comprises taking a plurality of measurements of at least one down-hole drilling condition at a bit of a drill string; generating a plurality of analog signals representative of the measurements; and multiplexing the analog signals at the bit.
U.S. Pat. No. 6,729,399 which is herein incorporated by reference for all that it contains, discloses a downhole tool for collecting data from a subsurface formation. The tool is provided with a probe for testing and/or sampling an adjacent formation. The tool is also provided with a protector positioned about the probe for engaging and protecting the sidewall of the bore hole surrounding the probe. The protector prevents deterioration of the wellbore during the testing and/or sampling by the probe.
U.S. Pat. No. 6,964,301 which is herein incorporated by reference for all that it contains, discloses apparatuses and methods for extracting fluid from a subsurface formation. A downhole sampling tool with a probe having an internal wall capable of selectively diverting virgin fluids into virgin flow channels for sampling, while diverting contaminated fluids into contaminated flow channels to be discarded. The characteristics of the fluid passing through the channels of the probe may be measured. The data generated during sampling may be sent to a controller capable of generating data, communicating and/or sending command signals. The flow of fluid into the downhole tool may be selectively adjusted to optimize the flow of fluid into the channels by adjusting the internal wall within the probe and/or by adjusting the flow rates through the channels. The configuration of the internal wall and/or the flow rates may be automatically adjusted by the controller and/or manually manipulated to further optimize the fluid flow.
U.S. Pat. No. 6,986,282 which is herein incorporated by reference for all that it contains, discloses a method and apparatus to collect downhole data during a drilling operation via a downhole tool. A differential pressure is created by the difference between internal pressure of fluid passing through the downhole tool and the annular pressure in the wellbore. The apparatus includes a drill collar connectable to the downhole drilling, and has an opening extending into a chamber therein. A piston is positioned in the chamber and has a rod extending into the opening. The piston is movable between a closed position with the rod filling the opening, and an open position with the rod retracted into the chamber to form a cavity for receiving downhole fluid. A sensor is positioned in the rod for collecting data from fluid in the cavity. The apparatus may also be provided with a probe and/or hydraulic circuitry to facilitate the collection of data.
U.S. Pat. No. 6,568,487 which is herein incorporated by reference for all that it contains, discloses a tool for obtaining at least one parameter of interest of a subterranean formation in-situ, the tool comprising a carrier member, a selectively extendable member mounted on the carrier for isolating a portion of annulus, a port exposable to formation fluid in the isolated annulus space, a piston integrally disposed within the extendable member for urging the fluid into the port, and a sensor operatively associated with the port for detecting at least one parameter of interest of the fluid.